BS IEC 62396-5:2014
$142.49
Process management for avionics. Atmospheric radiation effects – Assessment of thermal neutron fluxes and single event effects in avionics systems
| Published By | Publication Date | Number of Pages |
| BSI | 2014 | 26 |
The purpose of this part of IEC 62396 is to provide a more precise definition of the threat that thermal neutrons pose to avionics as a second mechanism for inducing single event upset (SEU) in microelectronics. There are two main points that will be addressed in this part of IEC 62396 :
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a detailed evaluation of the existing literature on measurements of the thermal flux inside of airliners, and
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an enhanced compilation of the thermal neutron SEU cross-section in currently available SRAM devices (more than 20 different devices).
The net result of the reviews of these two different sets of data will be two ratios that are considered to be very important for leading to the ultimate objective of how large a threat is the SEU rate from thermal neutrons compared to the SEU threat from the high energy neutrons ( E >10 MeV). The threat from the high energy neutrons has been dealt with extensively in the literature and has been addressed by two standards ( IEC 62396‑1 in avionics and JESD89A [1] 1 in microelectronics on the ground). Neutrons with E > 1 MeV are considered for parts with geometries below 150 nm.
Reference is made to IEC 62396‑1:2012, 5.3.2, for smaller geometry parts below 150 nm which provides the neutron flux for energies above 1 MeV.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 4 | CONTENTS |
| 5 | FOREWORD |
| 7 | 1 Scope 2 Normative references 3 Terms and definitions 4 Overview of thermal neutron single event rate calculation |
| 9 | 5 Thermal neutron flux inside an airliner 5.1 Definition of thermal neutron 5.2 Overview 5.3 Background on aircraft measurements |
| 10 | 5.4 Calculational approach |
| 11 | 5.5 Processing of in-flight neutron flux data Tables Table 1 – Tabulation of the various atmospheric neutron measurements used |
| 12 | Figures Figure 1 – Atmospheric neutron spectra measured in four aircraft |
| 13 | Table 2 – Comparison of thermal and high energy neutron fluxes and their ratios |
| 14 | Table 3 – Calculated neutron fluxes in the Boeing 747 structure |
| 15 | 6 Thermal neutron SEU cross-sections 6.1 Overview of the issue 6.2 Mechanism involved |
| 17 | 6.3 Thermal neutron SEU cross-sections and Ratio-2 Figure 2 – Neutron cross-sections for boron-10 including total cross-section (red), total elastic cross-section (green) and (n,) nuclear capture cross-section (blue) |
| 18 | Table 4 – SRAM SEU cross-sections induced by thermal and high energy neutrons |
| 19 | 7 Recommendation for devices in avionics at the present time 7.1 General 7.2 Ratio-1 |
| 20 | 7.3 Ratio-2 7.4 Thermal neutron upset rate 8 Determining thermal neutron SEE rates for use in equipment assessments 8.1 Demonstration of thermal neutron immunity to SEE 8.1.1 Thermal neutron test 8.1.2 Absence of boron 10 (B10) |
| 21 | 8.2 Determination of thermal neutron SEE where there is no evidence of thermal neutron immunity 8.2.1 Results from thermal neutron testing 8.2.2 Conservative estimation 8.2.3 High voltage devices 9 Single event burn out in high voltage devices due to thermal neutrons |
| 22 | Bibliography |
